1. Field of the Invention
This invention relates to a method of molding, more particularly to a method of integrally molding a member to be molded onto a portion of a rigid member, and is concerned with a molding method being effectively utilized in manufacturing a connecting rod used in a crank device of a wiper system in a motor vehicle for example.
2. Description of Related Art
In general, in a wiper system for wiping a window glass of a motor vehicle, a crank device is used to convert rotary motion of a wiper motor into rocking motion of a wiper arm. In the crank device of this type, a connecting rod integrally molded (hereinafter referred to as "outsert molded") at opposite end portions of a rod with joint members made of resin may be used.
There is a known method of outsert molding of the joint member made of resin in the connecting rod of this type, wherein a small hole is formed as a portion to be positioned, at or near the end of the rod, and raised portions are formed at portions outside of a cavity of an outsert molding tool, whereby, when the rod is inserted into the cavity, the raised portions are coupled into the small hole, and the rod is properly positioned to the cavity, so that the center-aligned state of the rod and the joint member can be properly secured after the outsert molding.
However, in the method of outsert molding of the type described, such disadvantages are presented that, since the small hole is formed in the rod, the rod is lowered in mechanical strength. Moreover, since the small hole as being the portion to be positioned is exposed to the outside of the joint member after the outsert molding, the visual appearance is deteriorated, and further, center-alignment cannot be secured under the condition where the small hole cannot be formed.